CPU Usage, is Plex Transcoder.exe
Test 1: 1080p - HDR Tone mapping: ON
CPU: starting at 100% for 15 seconds, then up and down to 15-30 %
GPU: NOT IN USE
H/W acceleration: Disabled
Transcode to: 720 2 Mbps
Test 1.2: 1080p - HDR Tone mapping: OFF
CPU: starting at 100% for 25 seconds, then up and down to 15-30 %
GPU: NOT IN USE
H/W acceleration: Disabled.
Transcode to: 720 2 Mbps
Test 1.3: 1080p - HDR Tone mapping: OFF
CPU: 20%
GPU: 68%
(after a few minutes of playing CPU and GPU go down to 1% and shortly up every 10 to 15 seconds to 20/68)
H/W acceleration: Enabled.
Transcode to: 720 2 Mbps
Test 1.4: 1080p - HDR Tone mapping: ON
Same results as test 1.3
Test 2: 4K HDR - HDR Tone mapping: OFF
CPU: 20% all the time
GPU: 68%
H/W acceleration: Enabled
Transcode to: 1080 8 Mbps
Test 2.2: 4K HDR - HDR Tone mapping: ON
Same results as test 2
Thanks, this was a great exercise to do, gave me some useful info, and also seems things started working much better once I had setting turned of and back o1 time…
Now its using HW, and its much better :o)
To me it looks like CPU and RAM is more then enough, but if I want more performance I must have more GPU power…???
My motherboard is: Gigabyte Z370 HD3P-CF (U3E1)
with integrated: Intel UHD Graphics 630 (Gigabyte)
Could I buy a bigger better GPU and add that to this board? And disable the Intel 630, so the new GPU will be used, or even use both at the same time ??
Again, thanks a bunch, this is really helping me out 
(Also thanks to the others that made replies)